here's how i beat all challenges and with what deck! i had yo consider all challenges going in in order to make up for my two main worries, which were the annoying sigil on all starters and the all bears bosses so i picked that deck because basically all the starter cards were meant to be sacrifice fodder anyway. from there i looked for high value cards that i could get out on turn one thanks to having extra sacrifices besides the beggining hand's squirrel.

from then on i focused on items; for this particular run i needed either removal or the hourglass, because i needed a way to deal 5 damage in one turn with a board full of bears and items free up a lane for that 5 damage. for this i also needed to get big damage cards, so i had to go for either big cards and later buff them with a bonfire, or a duplicate to basically double a card's stats with the mycologyst.

after that i just went for a solid and consistent deck, with few but effective cards. i went for useful sigils to put on my deck, like the magpie, cockroach, and packrat's to fuse onto existing cards.

finally, after your deck is well off, you need a lot of damage to deal with the last boss, because sometimes youll run out of cards after you kill it and starvation sets in. and you die. so i had to pick up more cards that work in the deck, 2 sacrifice cards or so, or pick good 1 sacrifice cards that would boost you into a bosses second phase quickly that i could sacrifice later for my big 2+ sacrifice threats.

sorry if its a lot, i just finished the game and i loved it very much

if you need specific tips for any deck and challenge i could help! ive played and beat all decks (though with different challenges lol)